A single plate-type or two plate-type color solid pickup element (or color solid imaging element) has laminated on the surface thereon micro color filters composed of multicolor separation filter elements of red, green, and blue or of cyan, magenta, and yellow corresponding to each image element constituting the image pickup element. The production process for such a solid image pickup element is generally classified into a lamination process and an on-wafer process. The on-wafer process is described in, for example, U.S. Pat. Nos. 4,081,277, 3,271,345 and 3,707,373.
In the former process, a color solid image pickup element is prepared by separately forming a solid image pickup element base plate and a micro multicolor filter plate having disposed on a transparent support color separation filter elements corresponding to each image element of the solid image pickup element. The plates are then bonded to each other. On the other hand, in the latter process, a micro multicolor filter is formed directly on a solid image pickup element base plate.
Accordingly, the former process requires precise registration of each color separation filter element and each image element of a solid image pickup element before bonding the two plates. However, by using the latter process, it is possible to employ the process of forming the micro multicolor filter as a part of a semiconductor production process. Therefore, the latter process is said to be an inevitable technique for producing color solid image pickup elements at low cost.
In addition, as the latter process, there are a process of forming on a wafer having formed therein a number of regularly disposed solid image pickup elements color separation filter elements each corresponding to each image element of said solid image pickup elements to simultaneously form a number of color solid image pickup elements and a process (on-chip process) of forming a color separation filter element on a single solid image pickup element (chip) cut from the foregoing wafer having a large number of solid image pickup elements. These processes are all called "on-wafer process" in this specification.